[PATCH] media: i2c: Annotate struct i2c_atr with __counted_by

[Kees Cook]

Prepare for the coming implementation by GCC and Clang of the __counted_by
attribute. Flexible array members annotated with __counted_by can have
their accesses bounds-checked at run-time checking via CONFIG_UBSAN_BOUNDS
(for array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family
functions).

As found with Coccinelle[1], add __counted_by for struct i2c_atr.

[1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci

Cc: Wolfram Sang <wsa@xxxxxxxxxx>
Cc: Tomi Valkeinen <tomi.valkeinen@xxxxxxxxxxxxxxxx>
Cc: Luca Ceresoli <luca.ceresoli@xxxxxxxxxxx>
Cc: Nathan Chancellor <nathan@xxxxxxxxxx>
Cc: Nick Desaulniers <ndesaulniers@xxxxxxxxxx>
Cc: Tom Rix <trix@xxxxxxxxxx>
Cc: linux-i2c@xxxxxxxxxxxxxxx
Cc: llvm@xxxxxxxxxxxxxxx
Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
---
 drivers/i2c/i2c-atr.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/i2c/i2c-atr.c b/drivers/i2c/i2c-atr.c
index 8ca1daadec93..f21475ae5921 100644
--- a/drivers/i2c/i2c-atr.c
+++ b/drivers/i2c/i2c-atr.c
@@ -94,7 +94,7 @@ struct i2c_atr {
 
 	struct notifier_block i2c_nb;
 
-	struct i2c_adapter *adapter[];
+	struct i2c_adapter *adapter[] __counted_by(max_adapters);
 };
 
 static struct i2c_atr_alias_pair *
-- 
2.34.1